Spring foundation- for beds



J. H. CRANE. FOUNDATION SPRING FOR BEDS, sous. 6m.

M21037. Patented Feb. 7, 1860.

Invert 07;

UNITED STATES PATENT OFFICE.

JOHN H. CRANE, OF CI-IARLESTOWN, MASSACHUSETTS.

SPRING FOUNDATION FOR BEDS, SOFAS, &c.

Specification of Letters Patent No.

To all whom it may concern:

Be it known that I, JOHN H. CRANE, of Charlestown, in Middlesex county, in the State of Massachusetts, have invented certain new and useful Improvements in Spring Foundations for Beds, Sofas, Chairs, &c.; and I do hereby declare that the following, taken in connection with the drawings that accompany and form part of this specification, is a description of my invention so full and exact as to enable those skilled in the art to practice it.

In my invention the bedding, or upholstering, rests directly upon such slats of wood as are commonly used for similar purposes. These slats rest, toward each of their ends, upon pieces of curvalinear outline, which may or may not be springs in themselves. The slats rest upon the convex side of these pieces which, in turn, rest upon or are fixed to supports beneath, which may be slats resting upon the bedstead, or a frame supported thereby, and arranged parallel with the upper slats, or the supports for these may be bars or slats arranged transversely to them and common to all. The ends of the slats are connected to the free ends of the curvalinear pieces by links, which may or may not be elastic as will be explained beyond. In allv spring beds with which I am acquained, which are made with a combination of slats and springs, the distances of the points of support of the slat with reference to its center are not materially changed by the effect of weight upon the slat. In such beds weight, as applied to them in their ordinary use, causes a disagreeable deflection or sag in the center of the slats, to prevent this is the object of the United States Patent No. 13,265.

To lessen the amount of the sag of the slats at their centers, and to produce an elastic or spring foundation, for the purposes before mentioned, by elasticity in the slats, curvalinear pieces, and links, or in any of them, is the object of my invention. Its nature consists in the peculiar arrangement and combination of parts, whereby the bearings of the slats shift toward their centers and whereby the ends of the slats are drawn down into a reverse curve with the sag as the load upon the slats is increased, and whereby the elastic property of the foundation may 27,037, dated February 7, 1860.

be obtained by elasticity in all of the parts or 1n any of them.

In Figures 1, 2, and 3 the curvalinear plece ((4) 1s a spring, in which case the links 21)), which are connected to the free ends of a) and to the ends of the slat (a), may be made of rubber, or of some fabric containmg rubber, or they may be spiral springs or some other elastic medium, or they may be made nonelastic. It will be obvious that, as weight is applied to the upper slat, the pleces (a) will be compressed, and the outline of their curve changed, which draws away from the slat or slats the free ends of (a) this draws upon them in such a way as to lessen the sag of the slat, the points of support, which by compression of (a) have.

been brought nearer the center of (0) than they are in the normal position of the parts, acting as fulcrums, the weight being applied near the center of the slat, and the resistance near the ends thereof.

In Fig. 4 the pieces (a) are hinged as shown, and are not intended to be practically elastic; in this case then it will be obvious that there must either be elasticity in the links (6), or else that the ends of the slats would be bent over their points of support on (a) very much more than would be the case where as in Figs. 1, 2 and 3 the pieces (a) are elastic. I prefer therefore when the pieces (a) are made unelastic to employ elastic links.

To retain the pieces (a) in their relative position to the slats, I prefer to make the latter of the form shown in the drawing in section, as by this the pieces (a) are steadied, and strength of the slat in proportion to its weight increased.

Having described my invention, what I claim therein as new, and desire to secure by Letters Patent of the United States, is

The combination and arrangement of parts described as forming an elastic foundation for the purpose set forth; the same consisting of the slats (0), curvalinear pieces (a), and links (7)) acting together substantially in the specified manner.

JOHN H. CRANE.

Witnesses:

J. B. CROSBY, W. B. GLEAsoN, 

